<?xml version="1.0" encoding="utf-8"?>
<xbrl
  xml:lang="en-US"
  xmlns="http://www.xbrl.org/2003/instance"
  xmlns:dei="http://xbrl.sec.gov/dei/2021"
  xmlns:link="http://www.xbrl.org/2003/linkbase"
  xmlns:xlink="http://www.w3.org/1999/xlink"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
    <link:schemaRef xlink:href="seer-20230615.xsd" xlink:type="simple"/>
    <context id="icb7b618e5a9c4e7c868dd7f2a59af9cc_D20230615-20230615">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0001726445</identifier>
        </entity>
        <period>
            <startDate>2023-06-15</startDate>
            <endDate>2023-06-15</endDate>
        </period>
    </context>
    <dei:DocumentFiscalYearFocus
      contextRef="icb7b618e5a9c4e7c868dd7f2a59af9cc_D20230615-20230615"
      id="id3VybDovL2RvY3MudjEvZG9jOjgxY2NlZmM2MGE3ODRmZDY4NWM3OTVjN2Q2YjUwODZhL3NlYzo4MWNjZWZjNjBhNzg0ZmQ2ODVjNzk1YzdkNmI1MDg2YV80L2ZyYWc6NmE1ZDQ2MTA2NWJlNGNkNzgzNjMyNzdhZjk4ZmNiZTQvdGFibGU6OTFmM2VlZWY5ZTViNDk0NGE3ODYzNzEzZGIzOGRiM2MvdGFibGVyYW5nZTo5MWYzZWVlZjllNWI0OTQ0YTc4NjM3MTNkYjM4ZGIzY18yLTEtMS0xLTE5Nzc4NA_88b9eaf2-a608-438c-84b6-6b8cdf2d96e1"
      xsi:nil="true"/>
    <dei:CurrentFiscalYearEndDate
      contextRef="icb7b618e5a9c4e7c868dd7f2a59af9cc_D20230615-20230615"
      id="id3VybDovL2RvY3MudjEvZG9jOjgxY2NlZmM2MGE3ODRmZDY4NWM3OTVjN2Q2YjUwODZhL3NlYzo4MWNjZWZjNjBhNzg0ZmQ2ODVjNzk1YzdkNmI1MDg2YV80L2ZyYWc6NmE1ZDQ2MTA2NWJlNGNkNzgzNjMyNzdhZjk4ZmNiZTQvdGFibGU6OTFmM2VlZWY5ZTViNDk0NGE3ODYzNzEzZGIzOGRiM2MvdGFibGVyYW5nZTo5MWYzZWVlZjllNWI0OTQ0YTc4NjM3MTNkYjM4ZGIzY18zLTEtMS0xLTIwMzM2NQ_d9105503-cd71-4cce-8753-fcd5aa043e91">--12-31</dei:CurrentFiscalYearEndDate>
    <dei:DocumentFiscalPeriodFocus
      contextRef="icb7b618e5a9c4e7c868dd7f2a59af9cc_D20230615-20230615"
      id="id3VybDovL2RvY3MudjEvZG9jOjgxY2NlZmM2MGE3ODRmZDY4NWM3OTVjN2Q2YjUwODZhL3NlYzo4MWNjZWZjNjBhNzg0ZmQ2ODVjNzk1YzdkNmI1MDg2YV80L2ZyYWc6NmE1ZDQ2MTA2NWJlNGNkNzgzNjMyNzdhZjk4ZmNiZTQvdGFibGU6OTFmM2VlZWY5ZTViNDk0NGE3ODYzNzEzZGIzOGRiM2MvdGFibGVyYW5nZTo5MWYzZWVlZjllNWI0OTQ0YTc4NjM3MTNkYjM4ZGIzY18zLTEtMS0xLTE5Nzc4NA_81495791-99b4-446e-ae25-67e95a7b0449"
      xsi:nil="true"/>
    <dei:AmendmentFlag
      contextRef="icb7b618e5a9c4e7c868dd7f2a59af9cc_D20230615-20230615"
      id="id3VybDovL2RvY3MudjEvZG9jOjgxY2NlZmM2MGE3ODRmZDY4NWM3OTVjN2Q2YjUwODZhL3NlYzo4MWNjZWZjNjBhNzg0ZmQ2ODVjNzk1YzdkNmI1MDg2YV80L2ZyYWc6NmE1ZDQ2MTA2NWJlNGNkNzgzNjMyNzdhZjk4ZmNiZTQvdGFibGU6OTFmM2VlZWY5ZTViNDk0NGE3ODYzNzEzZGIzOGRiM2MvdGFibGVyYW5nZTo5MWYzZWVlZjllNWI0OTQ0YTc4NjM3MTNkYjM4ZGIzY180LTEtMS0xLTE5Nzc4NA_056c806a-d9c9-43ff-806e-f8def552405a">false</dei:AmendmentFlag>
    <dei:EntityCentralIndexKey
      contextRef="icb7b618e5a9c4e7c868dd7f2a59af9cc_D20230615-20230615"
      id="id3VybDovL2RvY3MudjEvZG9jOjgxY2NlZmM2MGE3ODRmZDY4NWM3OTVjN2Q2YjUwODZhL3NlYzo4MWNjZWZjNjBhNzg0ZmQ2ODVjNzk1YzdkNmI1MDg2YV80L2ZyYWc6NmE1ZDQ2MTA2NWJlNGNkNzgzNjMyNzdhZjk4ZmNiZTQvdGFibGU6OTFmM2VlZWY5ZTViNDk0NGE3ODYzNzEzZGIzOGRiM2MvdGFibGVyYW5nZTo5MWYzZWVlZjllNWI0OTQ0YTc4NjM3MTNkYjM4ZGIzY181LTEtMS0xLTE5Nzc4NA_4fc8b265-cb59-4ba2-8ac7-e31524c0d3ff">0001726445</dei:EntityCentralIndexKey>
    <dei:DocumentType
      contextRef="icb7b618e5a9c4e7c868dd7f2a59af9cc_D20230615-20230615"
      id="id3VybDovL2RvY3MudjEvZG9jOjgxY2NlZmM2MGE3ODRmZDY4NWM3OTVjN2Q2YjUwODZhL3NlYzo4MWNjZWZjNjBhNzg0ZmQ2ODVjNzk1YzdkNmI1MDg2YV8xL2ZyYWc6NDFmNWQyYmM4Y2EyNDQ3ZThmNzViYWI2NmI5MzRlNTMvdGV4dHJlZ2lvbjo0MWY1ZDJiYzhjYTI0NDdlOGY3NWJhYjY2YjkzNGU1M18xMjg1_40962d0f-ad4d-44b5-b61e-6e6a4534d249">8-K</dei:DocumentType>
    <dei:DocumentPeriodEndDate
      contextRef="icb7b618e5a9c4e7c868dd7f2a59af9cc_D20230615-20230615"
      id="id3VybDovL2RvY3MudjEvZG9jOjgxY2NlZmM2MGE3ODRmZDY4NWM3OTVjN2Q2YjUwODZhL3NlYzo4MWNjZWZjNjBhNzg0ZmQ2ODVjNzk1YzdkNmI1MDg2YV8xL2ZyYWc6NDFmNWQyYmM4Y2EyNDQ3ZThmNzViYWI2NmI5MzRlNTMvdGV4dHJlZ2lvbjo0MWY1ZDJiYzhjYTI0NDdlOGY3NWJhYjY2YjkzNGU1M18xMjgw_a593ab86-2fcf-44e6-94f7-311a65697b31">2023-06-15</dei:DocumentPeriodEndDate>
    <dei:EntityRegistrantName
      contextRef="icb7b618e5a9c4e7c868dd7f2a59af9cc_D20230615-20230615"
      id="id3VybDovL2RvY3MudjEvZG9jOjgxY2NlZmM2MGE3ODRmZDY4NWM3OTVjN2Q2YjUwODZhL3NlYzo4MWNjZWZjNjBhNzg0ZmQ2ODVjNzk1YzdkNmI1MDg2YV8xL2ZyYWc6NDFmNWQyYmM4Y2EyNDQ3ZThmNzViYWI2NmI5MzRlNTMvdGV4dHJlZ2lvbjo0MWY1ZDJiYzhjYTI0NDdlOGY3NWJhYjY2YjkzNGU1M18xMjgx_f5a6d7bc-9af5-4ef0-8366-f62379f18d39">Seer, Inc.</dei:EntityRegistrantName>
    <dei:EntityIncorporationStateCountryCode
      contextRef="icb7b618e5a9c4e7c868dd7f2a59af9cc_D20230615-20230615"
      id="id3VybDovL2RvY3MudjEvZG9jOjgxY2NlZmM2MGE3ODRmZDY4NWM3OTVjN2Q2YjUwODZhL3NlYzo4MWNjZWZjNjBhNzg0ZmQ2ODVjNzk1YzdkNmI1MDg2YV8xL2ZyYWc6NDFmNWQyYmM4Y2EyNDQ3ZThmNzViYWI2NmI5MzRlNTMvdGFibGU6ODdhOWFiNjhiM2RmNDAwYjliY2EzODU1Y2QwNTA1ZDAvdGFibGVyYW5nZTo4N2E5YWI2OGIzZGY0MDBiOWJjYTM4NTVjZDA1MDVkMF8wLTAtMS0xLTE5Nzc4NA_73bbda2f-dd4c-421e-a679-bbc985a0bde6">DE</dei:EntityIncorporationStateCountryCode>
    <dei:EntityFileNumber
      contextRef="icb7b618e5a9c4e7c868dd7f2a59af9cc_D20230615-20230615"
      id="id3VybDovL2RvY3MudjEvZG9jOjgxY2NlZmM2MGE3ODRmZDY4NWM3OTVjN2Q2YjUwODZhL3NlYzo4MWNjZWZjNjBhNzg0ZmQ2ODVjNzk1YzdkNmI1MDg2YV8xL2ZyYWc6NDFmNWQyYmM4Y2EyNDQ3ZThmNzViYWI2NmI5MzRlNTMvdGFibGU6ODdhOWFiNjhiM2RmNDAwYjliY2EzODU1Y2QwNTA1ZDAvdGFibGVyYW5nZTo4N2E5YWI2OGIzZGY0MDBiOWJjYTM4NTVjZDA1MDVkMF8wLTItMS0xLTE5Nzc4NA_db70f30c-be52-4a05-8cda-f36e1dcd3170">001-39747</dei:EntityFileNumber>
    <dei:EntityTaxIdentificationNumber
      contextRef="icb7b618e5a9c4e7c868dd7f2a59af9cc_D20230615-20230615"
      id="id3VybDovL2RvY3MudjEvZG9jOjgxY2NlZmM2MGE3ODRmZDY4NWM3OTVjN2Q2YjUwODZhL3NlYzo4MWNjZWZjNjBhNzg0ZmQ2ODVjNzk1YzdkNmI1MDg2YV8xL2ZyYWc6NDFmNWQyYmM4Y2EyNDQ3ZThmNzViYWI2NmI5MzRlNTMvdGFibGU6ODdhOWFiNjhiM2RmNDAwYjliY2EzODU1Y2QwNTA1ZDAvdGFibGVyYW5nZTo4N2E5YWI2OGIzZGY0MDBiOWJjYTM4NTVjZDA1MDVkMF8wLTQtMS0xLTE5Nzc4NA_206d38ed-69bc-4715-9ba7-c886080abaf6">82-1153150</dei:EntityTaxIdentificationNumber>
    <dei:EntityAddressAddressLine1
      contextRef="icb7b618e5a9c4e7c868dd7f2a59af9cc_D20230615-20230615"
      id="id3VybDovL2RvY3MudjEvZG9jOjgxY2NlZmM2MGE3ODRmZDY4NWM3OTVjN2Q2YjUwODZhL3NlYzo4MWNjZWZjNjBhNzg0ZmQ2ODVjNzk1YzdkNmI1MDg2YV8xL2ZyYWc6NDFmNWQyYmM4Y2EyNDQ3ZThmNzViYWI2NmI5MzRlNTMvdGV4dHJlZ2lvbjo0MWY1ZDJiYzhjYTI0NDdlOGY3NWJhYjY2YjkzNGU1M18xMjgy_6f98b802-d1f2-475d-acd0-36f2da1d82a5">3800 Bridge Parkway</dei:EntityAddressAddressLine1>
    <dei:EntityAddressAddressLine2
      contextRef="icb7b618e5a9c4e7c868dd7f2a59af9cc_D20230615-20230615"
      id="id3VybDovL2RvY3MudjEvZG9jOjgxY2NlZmM2MGE3ODRmZDY4NWM3OTVjN2Q2YjUwODZhL3NlYzo4MWNjZWZjNjBhNzg0ZmQ2ODVjNzk1YzdkNmI1MDg2YV8xL2ZyYWc6NDFmNWQyYmM4Y2EyNDQ3ZThmNzViYWI2NmI5MzRlNTMvdGV4dHJlZ2lvbjo0MWY1ZDJiYzhjYTI0NDdlOGY3NWJhYjY2YjkzNGU1M18xMjg2_63d13c4b-75a1-4acd-9f15-9ba5fcb82e44">Suite 102</dei:EntityAddressAddressLine2>
    <dei:EntityAddressCityOrTown
      contextRef="icb7b618e5a9c4e7c868dd7f2a59af9cc_D20230615-20230615"
      id="id3VybDovL2RvY3MudjEvZG9jOjgxY2NlZmM2MGE3ODRmZDY4NWM3OTVjN2Q2YjUwODZhL3NlYzo4MWNjZWZjNjBhNzg0ZmQ2ODVjNzk1YzdkNmI1MDg2YV8xL2ZyYWc6NDFmNWQyYmM4Y2EyNDQ3ZThmNzViYWI2NmI5MzRlNTMvdGV4dHJlZ2lvbjo0MWY1ZDJiYzhjYTI0NDdlOGY3NWJhYjY2YjkzNGU1M18xMjgz_c43cd296-b92d-47ab-874a-4ab0acfb5b67">Redwood City</dei:EntityAddressCityOrTown>
    <dei:EntityAddressStateOrProvince
      contextRef="icb7b618e5a9c4e7c868dd7f2a59af9cc_D20230615-20230615"
      id="id3VybDovL2RvY3MudjEvZG9jOjgxY2NlZmM2MGE3ODRmZDY4NWM3OTVjN2Q2YjUwODZhL3NlYzo4MWNjZWZjNjBhNzg0ZmQ2ODVjNzk1YzdkNmI1MDg2YV8xL2ZyYWc6NDFmNWQyYmM4Y2EyNDQ3ZThmNzViYWI2NmI5MzRlNTMvdGV4dHJlZ2lvbjo0MWY1ZDJiYzhjYTI0NDdlOGY3NWJhYjY2YjkzNGU1M18xMjg3_ef80d99d-3028-451c-8f56-805560fdbda1">CA</dei:EntityAddressStateOrProvince>
    <dei:EntityAddressPostalZipCode
      contextRef="icb7b618e5a9c4e7c868dd7f2a59af9cc_D20230615-20230615"
      id="id3VybDovL2RvY3MudjEvZG9jOjgxY2NlZmM2MGE3ODRmZDY4NWM3OTVjN2Q2YjUwODZhL3NlYzo4MWNjZWZjNjBhNzg0ZmQ2ODVjNzk1YzdkNmI1MDg2YV8xL2ZyYWc6NDFmNWQyYmM4Y2EyNDQ3ZThmNzViYWI2NmI5MzRlNTMvdGV4dHJlZ2lvbjo0MWY1ZDJiYzhjYTI0NDdlOGY3NWJhYjY2YjkzNGU1M18zNjk_d7734081-e359-43eb-b7ab-1ccc9c122d8a">94065</dei:EntityAddressPostalZipCode>
    <dei:CityAreaCode
      contextRef="icb7b618e5a9c4e7c868dd7f2a59af9cc_D20230615-20230615"
      id="id3VybDovL2RvY3MudjEvZG9jOjgxY2NlZmM2MGE3ODRmZDY4NWM3OTVjN2Q2YjUwODZhL3NlYzo4MWNjZWZjNjBhNzg0ZmQ2ODVjNzk1YzdkNmI1MDg2YV8xL2ZyYWc6NDFmNWQyYmM4Y2EyNDQ3ZThmNzViYWI2NmI5MzRlNTMvdGV4dHJlZ2lvbjo0MWY1ZDJiYzhjYTI0NDdlOGY3NWJhYjY2YjkzNGU1M180MzU_3968c465-2bb9-4230-8587-666d03a1b118">650</dei:CityAreaCode>
    <dei:LocalPhoneNumber
      contextRef="icb7b618e5a9c4e7c868dd7f2a59af9cc_D20230615-20230615"
      id="id3VybDovL2RvY3MudjEvZG9jOjgxY2NlZmM2MGE3ODRmZDY4NWM3OTVjN2Q2YjUwODZhL3NlYzo4MWNjZWZjNjBhNzg0ZmQ2ODVjNzk1YzdkNmI1MDg2YV8xL2ZyYWc6NDFmNWQyYmM4Y2EyNDQ3ZThmNzViYWI2NmI5MzRlNTMvdGV4dHJlZ2lvbjo0MWY1ZDJiYzhjYTI0NDdlOGY3NWJhYjY2YjkzNGU1M18xMjg4_2cb76999-0640-4783-b8de-2a939ef1c89d">453-0000</dei:LocalPhoneNumber>
    <dei:WrittenCommunications
      contextRef="icb7b618e5a9c4e7c868dd7f2a59af9cc_D20230615-20230615"
      id="id3VybDovL2RvY3MudjEvZG9jOjgxY2NlZmM2MGE3ODRmZDY4NWM3OTVjN2Q2YjUwODZhL3NlYzo4MWNjZWZjNjBhNzg0ZmQ2ODVjNzk1YzdkNmI1MDg2YV8xL2ZyYWc6NDFmNWQyYmM4Y2EyNDQ3ZThmNzViYWI2NmI5MzRlNTMvdGFibGU6MjFhYzlmNjQxZmM1NGQzZDg4OTRlMzJmOTU1NTYzN2QvdGFibGVyYW5nZToyMWFjOWY2NDFmYzU0ZDNkODg5NGUzMmY5NTU1NjM3ZF8wLTAtMS0xLTE5Nzc4NA_ee3ef3bf-25b4-4e71-ac6a-4f3543804301">false</dei:WrittenCommunications>
    <dei:SolicitingMaterial
      contextRef="icb7b618e5a9c4e7c868dd7f2a59af9cc_D20230615-20230615"
      id="id3VybDovL2RvY3MudjEvZG9jOjgxY2NlZmM2MGE3ODRmZDY4NWM3OTVjN2Q2YjUwODZhL3NlYzo4MWNjZWZjNjBhNzg0ZmQ2ODVjNzk1YzdkNmI1MDg2YV8xL2ZyYWc6NDFmNWQyYmM4Y2EyNDQ3ZThmNzViYWI2NmI5MzRlNTMvdGFibGU6MjFhYzlmNjQxZmM1NGQzZDg4OTRlMzJmOTU1NTYzN2QvdGFibGVyYW5nZToyMWFjOWY2NDFmYzU0ZDNkODg5NGUzMmY5NTU1NjM3ZF8xLTAtMS0xLTE5Nzc4NA_286d4e54-b3a8-4051-a94b-3a0b0afe5c50">false</dei:SolicitingMaterial>
    <dei:PreCommencementTenderOffer
      contextRef="icb7b618e5a9c4e7c868dd7f2a59af9cc_D20230615-20230615"
      id="id3VybDovL2RvY3MudjEvZG9jOjgxY2NlZmM2MGE3ODRmZDY4NWM3OTVjN2Q2YjUwODZhL3NlYzo4MWNjZWZjNjBhNzg0ZmQ2ODVjNzk1YzdkNmI1MDg2YV8xL2ZyYWc6NDFmNWQyYmM4Y2EyNDQ3ZThmNzViYWI2NmI5MzRlNTMvdGFibGU6MjFhYzlmNjQxZmM1NGQzZDg4OTRlMzJmOTU1NTYzN2QvdGFibGVyYW5nZToyMWFjOWY2NDFmYzU0ZDNkODg5NGUzMmY5NTU1NjM3ZF8yLTAtMS0xLTE5Nzc4NA_8923125a-b789-4dec-99aa-a24d92ceb6eb">false</dei:PreCommencementTenderOffer>
    <dei:PreCommencementIssuerTenderOffer
      contextRef="icb7b618e5a9c4e7c868dd7f2a59af9cc_D20230615-20230615"
      id="id3VybDovL2RvY3MudjEvZG9jOjgxY2NlZmM2MGE3ODRmZDY4NWM3OTVjN2Q2YjUwODZhL3NlYzo4MWNjZWZjNjBhNzg0ZmQ2ODVjNzk1YzdkNmI1MDg2YV8xL2ZyYWc6NDFmNWQyYmM4Y2EyNDQ3ZThmNzViYWI2NmI5MzRlNTMvdGFibGU6MjFhYzlmNjQxZmM1NGQzZDg4OTRlMzJmOTU1NTYzN2QvdGFibGVyYW5nZToyMWFjOWY2NDFmYzU0ZDNkODg5NGUzMmY5NTU1NjM3ZF8zLTAtMS0xLTE5Nzc4NA_d0e894fc-3528-4f1d-b77b-45dd043e02bd">false</dei:PreCommencementIssuerTenderOffer>
    <dei:Security12bTitle
      contextRef="icb7b618e5a9c4e7c868dd7f2a59af9cc_D20230615-20230615"
      id="id3VybDovL2RvY3MudjEvZG9jOjgxY2NlZmM2MGE3ODRmZDY4NWM3OTVjN2Q2YjUwODZhL3NlYzo4MWNjZWZjNjBhNzg0ZmQ2ODVjNzk1YzdkNmI1MDg2YV8xL2ZyYWc6NDFmNWQyYmM4Y2EyNDQ3ZThmNzViYWI2NmI5MzRlNTMvdGFibGU6ZmM3ZDBiZWYyZTRkNDViOWJiOTE3YWRhYzk1MDZkNDUvdGFibGVyYW5nZTpmYzdkMGJlZjJlNGQ0NWI5YmI5MTdhZGFjOTUwNmQ0NV8xLTAtMS0xLTE5Nzc4NA_a11674b5-dd05-4acb-b108-3ec68a97a835">Class A Common Stock, par value $0.00001 per share</dei:Security12bTitle>
    <dei:TradingSymbol
      contextRef="icb7b618e5a9c4e7c868dd7f2a59af9cc_D20230615-20230615"
      id="id3VybDovL2RvY3MudjEvZG9jOjgxY2NlZmM2MGE3ODRmZDY4NWM3OTVjN2Q2YjUwODZhL3NlYzo4MWNjZWZjNjBhNzg0ZmQ2ODVjNzk1YzdkNmI1MDg2YV8xL2ZyYWc6NDFmNWQyYmM4Y2EyNDQ3ZThmNzViYWI2NmI5MzRlNTMvdGFibGU6ZmM3ZDBiZWYyZTRkNDViOWJiOTE3YWRhYzk1MDZkNDUvdGFibGVyYW5nZTpmYzdkMGJlZjJlNGQ0NWI5YmI5MTdhZGFjOTUwNmQ0NV8xLTEtMS0xLTE5Nzc4NA_b900a47b-e8af-4809-a067-642e95f31e2e">SEER</dei:TradingSymbol>
    <dei:EntityEmergingGrowthCompany
      contextRef="icb7b618e5a9c4e7c868dd7f2a59af9cc_D20230615-20230615"
      id="id3VybDovL2RvY3MudjEvZG9jOjgxY2NlZmM2MGE3ODRmZDY4NWM3OTVjN2Q2YjUwODZhL3NlYzo4MWNjZWZjNjBhNzg0ZmQ2ODVjNzk1YzdkNmI1MDg2YV8xL2ZyYWc6NDFmNWQyYmM4Y2EyNDQ3ZThmNzViYWI2NmI5MzRlNTMvdGV4dHJlZ2lvbjo0MWY1ZDJiYzhjYTI0NDdlOGY3NWJhYjY2YjkzNGU1M18xMjg0_1084604b-020a-4cad-8b45-119fb3d7d5fc">false</dei:EntityEmergingGrowthCompany>
</xbrl>
